TWI480576B - Wide-angle lens - Google Patents

Description

Wide-angle lens

The present invention relates to a wide-angle lens.

The trend of today's automotive lenses (such as driving recorder lenses, reversing lenses, etc.) and camera lenses is constantly moving towards miniaturization, wide viewing angles and high resolution, resulting in miniaturization and lenses with wide viewing angles and high resolution. Demand has increased significantly. The conventional lens can no longer meet the needs of today, and it needs a lens with another new architecture to meet the needs of miniaturization, wide viewing angle and high resolution.

In view of this, the main object of the present invention is to provide a wide-angle lens with a short total lens length and a large viewing angle, but still has good optical performance, and the lens resolution can also meet the requirements.

The wide-angle lens of the present invention sequentially includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens from the object side to the image side along the optical axis. The first lens has a convex-concave lens having a negative refractive power, and the convex surface of the first lens faces the object side concave surface toward the image side. The second lens is a biconcave lens having a negative refractive power. The third lens has a positive refractive power and includes a convex surface facing the object side. The fourth lens has a convex-concave lens having a negative refractive power, and the convex surface of the fourth lens faces the object-side concave surface toward the image side. The fifth lens is a lenticular lens having a positive refractive power.

Wherein the sixth lens has a positive refractive power.

Wherein the sixth lens has a negative refractive power.

The wide-angle lens satisfies the following conditions: 0.01 f/TTL 0.2; wherein f is the effective focal length of the wide-angle lens, and TTL is the distance from the object side of the first lens to the imaging plane on the optical axis.

The first lens and the second lens satisfy the following conditions: 3 f ₁ /f ₂ 6; wherein f ₁ is the effective focal length of the first lens, and f ₂ is the effective focal length of the second lens.

The fourth lens satisfies the following conditions: -20 f ₄ /f -1; wherein f ₄ is the effective focal length of the fourth lens, and f is the effective focal length of the wide-angle lens.

The sixth lens satisfies the following conditions: -20 f ₆ /f 50; wherein f ₆ is the effective focal length of the sixth lens, and f is the effective focal length of the wide-angle lens.

The third lens satisfies the following conditions: -10 (R ₃₁ -R ₃₂ )/(R ₃₁ +R ₃₂ ) -0.1; wherein R ₃₁ is the radius of curvature of the side surface of the third lens, and R ₃₂ is the radius of curvature of the image side surface of the third lens.

The fifth lens satisfies the following conditions: -70 (R ₅₁ -R ₅₂ )/(R ₅₁ +R ₅₂ ) 20; wherein R ₅₁ is a radius of curvature of an object side surface of the fifth lens, and R ₅₂ is a curvature radius of an image side surface of the fifth lens.

The two faces of the first lens are spherical surfaces.

The first lens is made of a glass material.

The lens of each of the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens is at least one surface aspherical surface or both surfaces are aspherical surfaces.

The second lens, the third lens, the fourth lens, the fifth lens and the sixth lens are made of a plastic material.

The wide-angle lens of the present invention may further include an aperture disposed between the third lens and the fourth lens.

The above described objects, features, and advantages of the invention will be apparent from the description and appended claims

1, 2, 3, 4‧‧‧ wide-angle lens

L11, L21, L31, L41‧‧‧ first lens

L12, L22, L32, L42‧‧‧ second lens

L13, L23, L33, L43‧‧‧ third lens

L14, L24, L34, L44‧‧‧ fourth lens

L15, L25, L35, L45‧‧‧ fifth lens

L16, L26, L36, L46‧‧‧ sixth lens

ST1, ST2, ST3, ST4‧‧ ‧ aperture

OF1, OF2, OF3, OF4‧‧‧ Filters

IMA1, IMA2, IMA3, IMA4‧‧‧ imaging surface

OA1, OA2, OA3, OA4‧‧‧ optical axis

S11, S12, S13, S14, S15, S16, S17‧‧

S18, S19, S110, S111, S112, S113‧‧‧

S114, S115‧‧‧ face

S21, S22, S23, S24, S25, S26, S27‧‧

S28, S29, S210, S211, S212, S213‧‧‧

S214, S215‧‧‧

S31, S32, S33, S34, S35, S36, S37‧‧

S38, S39, S310, S311, S312, S313‧‧

S314, S315‧‧‧

S41, S42, S43, S44, S45, S46, S47‧‧

S48, S49, S410, S411, S412, S413‧‧

S414, S415‧‧‧

1 is a schematic view showing a lens configuration and an optical path of a first embodiment of a wide-angle lens according to the present invention.

Fig. 2A is a longitudinal spherical aberration diagram of the wide-angle lens of Fig. 1.

Fig. 2B is an astigmatic field curvature diagram of the wide-angle lens of Fig. 1.

Fig. 2C is a distortion diagram of the wide-angle lens of Fig. 1.

Fig. 3 is a view showing a lens configuration and an optical path of a second embodiment of the wide-angle lens according to the present invention.

Fig. 4A is a longitudinal spherical aberration diagram of the wide-angle lens of Fig. 3.

Fig. 4B is an astigmatic field curvature diagram of the wide-angle lens of Fig. 3.

Figure 4C is a distortion diagram of the wide-angle lens of Figure 3.

Fig. 5 is a view showing a lens configuration and an optical path of a third embodiment of the wide-angle lens according to the present invention.

Fig. 6A is a longitudinal spherical aberration diagram of the wide-angle lens of Fig. 5.

Fig. 6B is an astigmatic field curvature diagram of the wide-angle lens of Fig. 5.

Fig. 6C is a distortion diagram of the wide-angle lens of Fig. 5.

Fig. 7 is a view showing a lens configuration and an optical path of a fourth embodiment of the wide-angle lens according to the present invention.

Fig. 8A is a longitudinal spherical aberration diagram of the wide-angle lens of Fig. 7.

Fig. 8B is an astigmatic field curvature diagram of the wide-angle lens of Fig. 7.

Fig. 8C is a distortion diagram of the wide-angle lens of Fig. 7.

Please refer to FIG. 1 , which is the first embodiment of the wide-angle lens according to the present invention. A schematic diagram of the lens configuration and optical path of the embodiment. At the time of imaging, the light from the object side is finally imaged on the imaging plane IMA1. The wide-angle lens 1 includes a first lens L11, a second lens L12, a third lens L13, an aperture ST1, a fourth lens L14, and a fifth lens L15 in sequence from the object side to the image side along the optical axis OA1. A sixth lens L16 and a filter OF1. The first lens L11 is a convex-concave lens having a negative refractive power made of a glass material, the object side surface S11 is a convex surface, the image side surface S12 is a concave surface, and the object side surface S11 and the image side surface S12 are spherical surfaces. The second lens L12 is a biconcave lens having a negative refractive power made of a plastic material, and both the object side surface S13 and the image side surface S14 are aspherical surfaces. The third lens L13 is a convex-concave lens having a positive refractive power made of a plastic material, and the object side surface S15 is a concave surface of the convex image side surface S16, and both the object side surface S15 and the image side surface S16 are aspherical surfaces. The fourth lens L14 is a convex-concave lens having a negative refractive power made of a plastic material, and the object side surface S18 has a convex image side surface S19 as a concave surface, and the object side surface S18 and the image side surface S19 are aspherical surfaces. The fifth lens L15 is a lenticular lens having a positive refractive power made of a plastic material, and both the object side surface S110 and the image side surface S111 are aspherical surfaces. The sixth lens L16 is a convex-concave lens having a negative refractive power made of a plastic material, and the object side surface S112 is a concave surface of the convex image side surface S113, and both the object side surface S112 and the image side surface S113 are aspherical surfaces. The filter OF1 has a flat surface S114 and an image side surface S115.

In addition, in order to maintain good optical performance of the wide-angle lens of the present invention, the wide-angle lens 1 of the first embodiment is required to satisfy the following six conditions:

Wherein f1 is the effective focal length of the wide-angle lens 1, TTL1 is the distance from the object side S11 of the first lens L11 to the imaging plane IMA1 on the optical axis OA1, f1 ₁ is the effective focal length of the first lens L11, and f1 ₂ is the second lens L12 the effective focal length, f1 ₄ L14 is the effective focal length of the fourth lens, f1 ₆ L16 is the effective focal length of the sixth lens, R1 ₃₁ to the third lens L13 of the object side surface S15 of a radius of curvature, R1 ₃₂ is the image of the third lens L13 The radius of curvature of the side surface S16, R1 ₅₁ is the radius of curvature of the object side surface S110 of the fifth lens L15, and R1 ₅₂ is the radius of curvature of the image side surface S111 of the fifth lens L15.

By adopting the design of the above lens and aperture ST1, the wide-angle lens 1 can effectively shorten the total length of the lens, improve the viewing angle, effectively correct aberrations, and improve lens resolution.

Table 1 is the relevant parameter table of each lens of the wide-angle lens 1 in Fig. 1. Table 1 shows that the effective focal length of the wide-angle lens 1 of the present embodiment is equal to 0.8594 mm, the aperture value is equal to 2.4, the viewing angle is equal to 204.2°, and the total lens length is equal to 11.000 mm. .

The aspherical surface depression z of each lens in Table 1 is obtained by the following formula: z = ch ² /{1 + [1 - (k + 1) c ² h ² ] ^1/2 } + Ah ⁴ + Bh ⁶ + Ch ⁸ +Dh ¹⁰ +Eh ¹²

Where: c: curvature; h: vertical distance from any point on the lens surface to the optical axis; k: conic coefficient; A~E: aspheric coefficient.

Table 2 is a table of related parameters of the aspherical surface of each lens in Table 1, where k is a conical coefficient (Conic Constant) and A~E is an aspherical coefficient.

The wide-angle lens 1 of the first embodiment has an effective focal length f1=0.8594 mm, a distance TTL1=11.000 mm from the object side surface S11 of the first lens L11 to the imaging plane IMA1 on the optical axis OA1, and an effective focal length f1 _{1 of the} first lens L11 =- 8.39127 mm, the effective focal length f1 _{2 of the} second lens L12 is -1.86248 mm, the effective focal length of the fourth lens L14 is f1 ₄ = -7.0002 mm, and the effective focal length of the sixth lens L16 is f1 ₆ = -6.77844 mm, and the third lens L13 The radius of curvature R1 ₃₁ = 1.30450 mm of the object side surface S15, the radius of curvature R1 ₃₂ =6.00000 mm of the image side surface S16 of the third lens L13, and the radius of curvature R1 ₅₁ of the object side surface S110 of the fifth lens L15 = 1.15476 mm, the fifth lens L15 The radius of curvature of the image side S111 is R1 ₅₂ = -1.19538 mm. From the above data, f1/TTL1=0.0781, f1 ₁ /f1 ₂ =4.5054, f1 ₄ /f1=-8.1450, f1 ₆ /f1=-7.8870, R1 _{31 -} R1 ₃₂ ) / (R1 ₃₁ + R1 ₃₂ ) = -0.6428, (R1 ₅₁ - R1 ₅₂ ) / (R1 ₅₁ + R1 ₅₂ ) = -57.8577, all satisfying the above conditions (1) to (6) Requirements.

In addition, the optical performance of the wide-angle lens 1 of the first embodiment can also be achieved, which can be seen from the 2A to 2C drawings. Fig. 2A is a longitudinal Spherical Aberration diagram of the wide-angle lens 1 of the first embodiment. Fig. 2B is an astigmatism field curve diagram of the wide-angle lens 1 of the first embodiment. Fig. 2C is a distortion diagram of the wide-angle lens 1 of the first embodiment.

As can be seen from FIG. 2A, the wide-angle lens 1 of the first embodiment produces a longitudinal spherical aberration value of -0.15 mm to 0.05 mm for light having a wavelength of 436.000 nm, 546.000 nm, and 656.000 nm. From the 2B diagram (the three lines in the sagittal direction almost coincide, the three lines in the meridional direction also almost coincide, so that it seems that there are only two lines), it can be seen that the wide-angle lens 1 of the first embodiment has a wavelength of 436.000 nm. The ray of 546.000 nm and 656.000 nm has an astigmatic field curvature between -0.10 mm and 0.20 mm in the direction of the Tangential and the Sagittal direction. From the 2C figure (the three lines in the figure are almost coincident, so that there seems to be only one line), it can be seen that the wide-angle lens 1 of the first embodiment is different for the distortion of the light having a wavelength of 436.000 nm, 546.000 nm, and 656.000 nm. Between -180% and 10%. It can be seen that the longitudinal spherical aberration, the astigmatic field curvature, and the distortion of the wide-angle lens 1 of the first embodiment can be effectively corrected, thereby obtaining better optical performance.

Please refer to FIG. 3, which is a schematic diagram of a lens configuration and an optical path of a second embodiment of the wide-angle lens according to the present invention. At the time of imaging, the light from the object side is finally imaged on the imaging surface IMA2. The wide-angle lens 2 includes a first lens L21, a second lens L22, a third lens L23, an aperture ST2, a fourth lens L24, a fifth lens L25, and the like from the object side to the image side along the optical axis OA2. A sixth lens L26 and a filter OF2. The first lens L21 is a convex-concave lens having a negative refractive power made of a glass material, the object side surface S21 is a convex surface, the image side surface S22 is a concave surface, and the object side surface S21 and the image side surface S22 are spherical surfaces. The second lens L22 has a negative concave lens The refractive power is made of a plastic material, and both the object side S23 and the image side surface S24 are aspherical surfaces. The third lens L23 is a lenticular lens having a positive refractive power made of a plastic material, and both the object side surface S25 and the image side surface S26 are aspherical surfaces. The fourth lens L24 is a convex-concave lens having a negative refractive power made of a plastic material, and the object side surface S28 has a convex image side surface S29 as a concave surface, and the object side surface S28 and the image side surface S29 are aspherical surfaces. The fifth lens L25 is a lenticular lens having a positive refractive power made of a plastic material, and both the object side surface S210 and the image side surface S211 are aspherical surfaces. The sixth lens L26 is a convex-concave lens having a negative refractive power made of a plastic material, and the object side surface S212 has a convex image side surface S213 as a concave surface, and the object side surface S212 and the image side surface S213 are both aspherical surfaces. The filter side OF2 has a flat side surface S214 and an image side surface S215.

In addition, in order to maintain good optical performance of the wide-angle lens of the present invention, the wide-angle lens 2 of the second embodiment is required to satisfy the following six conditions:

Where f2 is the effective focal length of the wide-angle lens 2, TTL2 is the distance from the object side S21 of the first lens L21 to the imaging plane IMA2 on the optical axis OA2, f2 ₁ is the effective focal length of the first lens L21, and f2 ₂ is the second lens L22 the effective focal length, f2 ₄ as the effective focal length L24 of the fourth lens, f2 ₆ for the effective focal length of the sixth lens L26 of, R2 ₃₁ of the third lens L23 of the object side surface S25 of a radius of curvature, R2 ₃₂ as the image of the third lens L23 The radius of curvature of the side surface S26, R2 ₅₁ is the radius of curvature of the object side surface S210 of the fifth lens L25, and R2 ₅₂ is the radius of curvature of the image side surface S211 of the fifth lens L25.

By adopting the above-mentioned design of the lens and the aperture ST2, the wide-angle lens 2 can effectively shorten the total length of the lens, improve the viewing angle, effectively correct the aberration, and improve the lens resolution.

Table 3 is the relevant parameter table of each lens of the wide-angle lens 2 in FIG. 3. The data in Table 3 shows that the effective focal length of the wide-angle lens 2 of the present embodiment is equal to 1.0342 mm, the aperture value is equal to 2.4, the viewing angle is equal to 207.2°, and the total lens length is equal to 11.000 mm. .

The aspherical surface depression z of each lens in Table 3 is obtained by the following formula: z = ch ² /{1 + [1 - (k + 1) c ² h ² ] ^1/2 } + Ah ⁴ + Bh ⁶ + Ch ⁸ +Dh ¹⁰ +Eh ¹²

Where: c: curvature; h: vertical distance from any point on the lens surface to the optical axis; k: conic coefficient; A~E: aspheric coefficient.

Table 4 is a table of related parameters of the aspherical surface of each lens in Table 3, where k is a conical coefficient (Conic Constant) and A~E is an aspherical coefficient.

The wide-angle lens 2 of the second embodiment has an effective focal length f2=1.0342 mm, a distance TTL2=11.000 mm from the object side surface S21 of the first lens L21 to the imaging plane IMA2 on the optical axis OA2, and an effective focal length f2 _{1 of the} first lens L21 =- 9.24583mm, the effective focal length of the second lens L22 is f2 ₂ =-1.91628mm, the effective focal length of the fourth lens L24 is f2 ₄ = -10.0000mm, and the effective focal length of the sixth lens L26 is f2 ₆ = -3.17657mm, and the third lens L23 The radius of curvature of the object side surface S25 is R2 ₃₁ = 1.88581 mm, the radius of curvature of the image side surface S26 of the third lens L23 is R2 ₃₂ = - 7.00000 mm, and the radius of curvature of the object side surface S210 of the fifth lens L25 is R2 ₅₁ = 1.43575 mm, and the fifth lens The radius of curvature of the image side S211 of L25 is R2 ₅₂ = -1.03535mm. From the above data, f2/TTL2=0.0940, f2 ₁ /f2 ₂ =4.8249, f2 ₄ /f2=-9.6698, f2 ₆ /f2=-3.0717, (R2 _{31 -} R2 ₃₂ ) / (R2 ₃₁ + R2 ₃₂ ) = -1.7228, (R2 ₅₁ - R2 ₅₂ ) / (R2 ₅₁ + R2 ₅₂ ) = 6.1716, all satisfying the above conditions (7) to (12) Requirements.

In addition, the optical performance of the wide-angle lens 2 of the second embodiment can also be achieved, which can be seen from Figs. 4A to 4C. Fig. 4A is a longitudinal Spherical Aberration diagram of the wide-angle lens 2 of the second embodiment. Fig. 4B is an astigmatic field curve diagram of the wide-angle lens 2 of the second embodiment. Fig. 4C is a distortion diagram of the wide-angle lens 2 of the second embodiment.

As can be seen from FIG. 4A, the wide-angle lens 2 of the second embodiment has a wavelength of Light rays of 436.000 nm, 546.000 nm, and 656.000 nm produce a longitudinal spherical difference of between -0.10 mm and 0.10 mm. From the 4th diagram (the three lines in the sagittal direction almost coincide, the three lines in the meridional direction also almost coincide, so that it seems that there are only two lines), it can be seen that the wide-angle lens 2 of the second embodiment has a wavelength of 436.000 nm. The ray of 546.000 nm and 656.000 nm has an astigmatic field curvature between -0.20 mm and 0.05 mm in the direction of the Tangential and the Sagittal direction. From Fig. 4C (the three lines in the figure are almost coincident, so that there appears to be only one line), it can be seen that the wide-angle lens 2 of the second embodiment is different for the distortion of the light having a wavelength of 436.000 nm, 546.000 nm, and 656.000 nm. Between -160% and 0%. It can be seen that the longitudinal spherical aberration, the astigmatic field curvature, and the distortion of the wide-angle lens 2 of the second embodiment can be effectively corrected, thereby obtaining better optical performance.

Please refer to FIG. 5, which is a schematic diagram of a lens configuration and an optical path of a third embodiment of the wide-angle lens according to the present invention. At the time of imaging, the light from the object side is finally imaged on the imaging surface IMA3. The wide-angle lens 3 includes a first lens L31, a second lens L32, a third lens L33, an aperture ST3, a fourth lens L34, a fifth lens L35, and the like from the object side to the image side along the optical axis OA3. A sixth lens L36 and a filter OF3. The first lens L31 is a convex-concave lens having a negative refractive power made of a glass material, and the object side surface S11 has a convex image side surface S12 as a concave surface, and the object side surface S11 and the image side surface S12 are spherical surfaces. The second lens L32 is a biconcave lens having a negative refractive power made of a plastic material, and both the object side surface S33 and the image side surface S34 are aspherical surfaces. The third lens L33 is a lenticular lens having a positive refractive power made of a plastic material, and both the object side surface S35 and the image side surface S36 are aspherical surfaces. The fourth lens L34 is a convex-concave lens having a negative refractive power made of a plastic material, the object side surface S38 being a convex surface, the image side surface S39 being a concave surface, and the object side surface S38 and the image side surface S39 being aspherical surfaces. The fifth lens L35 is a lenticular lens having a positive refractive power made of a plastic material, and both the object side surface S310 and the image side surface S311 are aspherical surfaces. The sixth lens L36 is a convex-concave lens having a negative refractive power made of a plastic material, and the object side surface S312 has a convex image side surface S313 as a concave surface, and the object side surface S312 and the image side surface S313 are aspherical surfaces. Filter OF3 its object side S314 Both the image side surface S315 are flat.

In addition, in order to maintain good optical performance of the wide-angle lens of the present invention, the wide-angle lens 3 of the third embodiment is required to satisfy the following six conditions:

Where f3 is the effective focal length of the wide-angle lens 3, TTL3 is the distance from the object side S31 of the first lens L31 to the imaging plane IMA3 on the optical axis OA3, f3 ₁ is the effective focal length of the first lens L31, and f3 ₂ is the second lens L32 The effective focal length, f3 ₄ is the effective focal length of the fourth lens L34, f3 ₆ is the effective focal length of the sixth lens L36, R3 ₃₁ is the radius of curvature of the object side S35 of the third lens L33, and R3 ₃₂ is the image of the third lens L33 The radius of curvature of the side surface S36, R3 ₅₁ is the radius of curvature of the object side surface S310 of the fifth lens L35, and R3 ₅₂ is the radius of curvature of the image side surface S311 of the fifth lens L35.

By adopting the design of the above lens and aperture ST3, the wide-angle lens 3 can effectively shorten the total length of the lens, improve the viewing angle, effectively correct aberrations, and improve lens resolution.

Table 5 is a table of related parameters of the lenses of the wide-angle lens 3 in FIG. 5. Table 5 shows that the effective focal length of the wide-angle lens 3 of the present embodiment is equal to 1.0677 mm, the aperture value is equal to 2.8, the angle of view is equal to 180.7°, and the total length of the lens is equal to 10.919 mm. .

The aspherical surface depression z of each lens in Table 5 is obtained by the following formula: z = ch ² /{1 + [1 - (k + 1) c ² h ² ] ^1/2 } + Ah ⁴ + Bh ⁶ + Ch ⁸ +Dh ¹⁰ +Eh ¹²

Where: c: curvature; h: the vertical distance from any point on the lens surface to the optical axis; k: conic coefficient; A~E: aspheric coefficient.

Table 6 is the relevant parameter table of the aspherical surface of each lens in Table 5, where k is the conic coefficient (Conic Constant) and A~E is the aspherical coefficient.

The wide-angle lens 3 of the third embodiment has an effective focal length f3=1.0677 mm, a distance TTL3=10.919 mm from the object side surface S31 of the first lens L31 to the imaging plane IMA3 on the optical axis OA3, and an effective focal length f3 _{1 of the} first lens L31 =- 8.68560mm, effective focal length f3 _{2 of the} second lens L32 = - 1.92412mm, effective focal length f3 _{4 of the} fourth lens L34 = -8.7391mm, effective focal length of the sixth lens L36 f3 ₆ = - 3.69033mm, the third lens L33 The radius of curvature R3 _{31 of the} object side S35 is 1.81783 mm, the radius of curvature R3 ₃₂ of the image side surface S36 of the third lens L33 is -6.997855 mm, and the radius of curvature of the object side surface S310 of the fifth lens L35 is R3 ₅₁ = 1.31412 mm, the fifth lens The radius of curvature of the image side S311 of the L35 is R3 ₅₂ = -1.10712 mm. From the above data, f3/TTL3 = 0.0978, f3 ₁ / f3 ₂ = 4.5141, f3 ₄ / f3 = -8.1850, f3 ₆ / f3 = -3.4564, (R3 _{31 -} R3 ₃₂ ) / (R3 ₃₁ + R3 ₃₂ ) = -1.7045, (R3 _{51 -} R3 ₅₂ ) / (R3 ₅₁ + R3 ₅₂ ) = 11.66, all satisfying the above conditions (13) to (18) Requirements.

Further, the optical performance of the wide-angle lens 3 of the third embodiment can also be achieved, which can be seen from Figs. 6A to 6C. Fig. 6A is a longitudinal Spherical Aberration diagram of the wide-angle lens 3 of the third embodiment. Fig. 6B is an astigmatism field curve diagram of the wide-angle lens 3 of the third embodiment. Fig. 6C is a distortion diagram of the wide-angle lens 3 of the third embodiment.

As can be seen from Fig. 6A, the wide-angle lens 3 of the third embodiment produces a longitudinal spherical aberration value of -0.15 mm to 0.05 mm for light having a wavelength of 436.000 nm, 546.000 nm, and 656.000 nm. From the 6th B (the three lines in the sagittal direction almost coincide, the three lines in the meridional direction also almost coincide, so that it seems that there are only two lines), it can be seen that the wide-angle lens 3 of the third embodiment has a wavelength of 436.000 nm. The ray of 546.000 nm and 656.000 nm has an astigmatic field curvature between -0.10 mm and 0.05 mm in the direction of the Tangential and the Sagittal direction. From Fig. 6C (the three lines in the figure are almost coincident, so that there appears to be only one line), it can be seen that the wide-angle lens 3 of the third embodiment is different for the distortion of the light having a wavelength of 436.000 nm, 546.000 nm, and 656.000 nm. Between -160% and 0%. The wide-angle lens 3 of the third embodiment is apparent The longitudinal spherical aberration, astigmatic field curvature, and distortion can be effectively corrected to obtain better optical performance.

Please refer to FIG. 7. FIG. 7 is a schematic diagram of a lens configuration and an optical path of a fourth embodiment of the wide-angle lens according to the present invention. At the time of imaging, the light from the object side is finally imaged on the image plane IMA4. The wide-angle lens 4 sequentially includes a first lens L41, a second lens L42, a third lens L43, an aperture ST4, a fourth lens L44, and a fifth lens L45 from the object side to the image side along the optical axis OA4. A sixth lens L46 and a filter OF4. The first lens L41 is a convex-concave lens having a negative refractive power made of a glass material, and the object side surface S41 has a convex image side surface S42 as a concave surface, and the object side surface S41 and the image side surface S42 are spherical surfaces. The second lens L42 is a biconcave lens having a negative refractive power made of a plastic material, and both the object side surface S43 and the image side surface S44 are aspherical surfaces. The third lens L43 is a lenticular lens having a positive refractive power made of a plastic material, and both the object side surface S45 and the image side surface S46 are aspherical surfaces. The fourth lens L44 is a convex-concave lens having a negative refractive power made of a plastic material, the object side surface S48 being a convex surface, the image side surface S49 being a concave surface, and the object side surface S48 and the image side surface S49 being aspherical surfaces. The fifth lens L45 is a lenticular lens having a positive refractive power made of a plastic material, and both the object side surface S410 and the image side surface S411 are aspherical surfaces. The sixth lens L46 is a meniscus lens having a positive refractive power made of a plastic material, and the object side surface S412 has a concave image side surface S413 as a convex surface, and the object side surface S412 and the image side surface S413 are aspherical surfaces. The filter OF4 has a flat surface S414 and an image side surface S415.

In addition, in order to maintain good optical performance of the wide-angle lens of the present invention, the wide-angle lens 4 of the fourth embodiment is required to satisfy the following six conditions:

Where f4 is the effective focal length of the wide-angle lens 4, TTL4 is the distance from the object side S41 of the first lens L41 to the imaging plane IMA4 on the optical axis OA4, f4 ₁ is the effective focal length of the first lens L41, and f4 ₂ is the second lens L42 The effective focal length, f4 ₄ is the effective focal length of the fourth lens L44, f4 ₆ is the effective focal length of the sixth lens L46, R4 ₃₁ is the radius of curvature of the object side S45 of the third lens L43, and R4 ₃₂ is the image of the third lens L43 The radius of curvature of the side surface S46, R4 ₅₁ is the radius of curvature of the object side surface S410 of the fifth lens L45, and R4 ₅₂ is the radius of curvature of the image side surface S411 of the fifth lens L45.

By adopting the above-mentioned design of the lens and the aperture ST4, the wide-angle lens 4 can effectively shorten the total length of the lens, improve the viewing angle, effectively correct the aberration, and improve the lens resolution.

Table 7 is the relevant parameter table of each lens of the wide-angle lens 4 in Fig. 7. The data in Table 7 shows that the effective focal length of the wide-angle lens 4 of the present embodiment is equal to 0.8462 mm, the aperture value is equal to 2.6, the viewing angle is equal to 205.4°, and the total lens length is equal to 11.000 mm. .

The aspherical surface depression z of each lens in Table 7 is obtained by the following formula: z = ch ² /{1 + [1 - (k + 1) c ² h ² ] ^1/2 } + Ah ⁴ + Bh ⁶ + Ch ⁸ +Dh ¹⁰ +Eh ¹²

Where: c: curvature; h: vertical distance from any point on the lens surface to the optical axis; k: conic coefficient; A~E: aspheric coefficient.

Table 8 is the relevant parameter table of the aspherical surface of each lens in Table 7, where k is the conic coefficient (Conic Constant) and A~E is the aspherical coefficient.

The wide-angle lens 4 of the fourth embodiment has an effective focal length f4=0.8462 mm, a distance TTL4=11.000 mm from the object side surface S41 of the first lens L41 to the imaging plane IMA4 on the optical axis OA4, and an effective focal length f4 _{1 of the} first lens L41. 9.55820mm, the effective focal length of the second lens L42 is f4 ₂ =-1.87508mm, the effective focal length of the fourth lens L44 is f4 ₄ =-9.9999mm, and the effective focal length of the sixth lens L46 is f4 ₆ =32.54607mm, and the third lens L43 The radius of curvature of the side surface S45 is R4 ₃₁ =1.78951 mm, the radius of curvature of the image side surface S46 of the third lens L43 is R4 ₃₂ = -5.203030 mm, and the radius of curvature of the object side surface S410 of the fifth lens L45 is R4 ₅₁ = 2.294497 mm, and the fifth lens L45 The curvature radius R4 ₅₂ of the image side S411 is -1.15849 mm. From the above data, f4/TTL4=0.0769, f4 ₁ /f4 ₂ =5.0975, f4 ₄ /f4=-11.8173, f4 ₆ /f4=38.4608, (R4) ₃₁ - R4 ₃₂ ) / (R4 ₃₁ + R4 ₃₂ ) = -2.0342, (R4 ₅₁ - R4 ₅₂ ) / (R4 ₅₁ + R4 ₅₂ ) = 3.0387, all satisfying the requirements of the above conditions (19) to (24) .

In addition, the optical performance of the wide-angle lens 4 of the fourth embodiment can also be achieved, which can be seen from Figs. 8A to 8C. Fig. 8A is a longitudinal Spherical Aberration diagram of the wide-angle lens 4 of the fourth embodiment. Fig. 8B is an astigmatism field curve diagram of the wide-angle lens 4 of the fourth embodiment. Fig. 8C is a distortion diagram of the wide-angle lens 4 of the fourth embodiment.

As can be seen from Fig. 8A, the wide-angle lens 4 of the fourth embodiment produces a longitudinal spherical aberration value of -0.15 mm to 0.05 mm for light having a wavelength of 436.000 nm, 546.000 nm, and 656.000 nm. From the 8th figure (the three lines in the sagittal direction almost coincide, the three lines in the meridional direction also almost coincide, so that it seems that there are only two lines), it can be seen that the wide-angle lens 4 of the fourth embodiment has a wavelength of 436.000 nm. The ray of 546.000 nm and 656.000 nm has an astigmatic field curvature between -0.15 mm and 0.10 mm in the direction of the Tangential and the Sagittal direction. From Fig. 8C (the three lines in the figure are almost coincident, so that it seems that there is only one line), it can be seen that the wide-angle lens 4 of the fourth embodiment is different for the distortion of the light having a wavelength of 436.000 nm, 546.000 nm, and 656.000 nm. Between -160% and 0%. It can be seen that the longitudinal spherical aberration, the astigmatic field curvature, and the distortion of the wide-angle lens 4 of the fourth embodiment can be effectively corrected, thereby obtaining better optical performance.

In the above embodiment, the object side surface and the image side surface of the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens are both aspherical surfaces, but it can be understood that if the second lens, the third lens, It is also within the scope of the invention to change each of the fourth, fifth and sixth lenses to at least one aspherical surface.

Although the present invention has been described above by way of a preferred embodiment, it is not intended to limit the invention, and any one skilled in the art can still make it without departing from the spirit and scope of the invention. There are a few changes and modifications, and therefore the scope of the invention is defined by the scope of the appended claims.

1‧‧‧ wide-angle lens

L11‧‧‧ first lens

L12‧‧‧ second lens

L13‧‧‧ third lens

L14‧‧‧4th lens

L15‧‧‧ fifth lens

L16‧‧‧ sixth lens

ST1‧‧‧ aperture

OF1‧‧‧Filter

OA1‧‧‧ optical axis

IMA1‧‧‧ imaging surface

S11, S12, S13, S14, S15‧‧

S16, S17, S18, S19, S110‧‧‧

S111, S112, S113, S114, S115‧‧‧

Claims (14)

A wide-angle lens includes, in order from the object side to the image side along the optical axis, a first lens, wherein the first lens has a convex-concave lens having a negative refractive power, and a convex surface of the first lens faces the object side concave surface toward the image side; a second lens, the second lens is a biconcave lens having a negative refractive power; a third lens having a positive refractive power and comprising a convex surface facing the object side; a fourth lens, the fourth lens being convex and concave The lens has a negative refractive power, the convex surface of the fourth lens faces the object side concave surface toward the image side; a fifth lens, the fifth lens has a positive refractive power; and a sixth lens. The wide-angle lens of claim 1, wherein the sixth lens has a positive refractive power. The wide-angle lens of claim 1, wherein the sixth lens has a negative refractive power. The wide-angle lens of claim 1, wherein the wide-angle lens satisfies the following conditions: Where f is the effective focal length of the wide-angle lens, and TTL is the distance from the object side of the first lens to the imaging surface on the optical axis. The wide-angle lens of claim 1, wherein the first lens and the second lens satisfy the following conditions: Where f _{1 is} the effective focal length of the first lens and f _{2 is} the effective focal length of the second lens. The wide-angle lens of claim 1, wherein the fourth lens satisfies the following conditions: Where f _{4 is} the effective focal length of the fourth lens, and f is the effective focal length of the wide-angle lens. The wide-angle lens of claim 1, wherein the sixth lens satisfies the following conditions: Where f _{6 is} the effective focal length of the sixth lens, and f is the effective focal length of the wide-angle lens. The wide-angle lens of claim 1, wherein the third lens satisfies the following conditions: Wherein R _{31 is a} radius of curvature of an object side surface of the third lens, and R _{32 is a} radius of curvature of an image side surface of the third lens. The wide-angle lens of claim 1, wherein the fifth lens satisfies the following conditions: Where R _{51 is} the radius of curvature of the object side surface of the fifth lens, and R _{52 is} the radius of curvature of the image side surface of the fifth lens. The wide-angle lens of claim 1, wherein the two faces of the first lens are spherical surfaces. The wide-angle lens of claim 1, wherein the first lens is made of a glass material. The wide-angle lens of claim 1, wherein at least one side of the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens are aspherical surfaces or two The faces are all aspherical surfaces. The wide-angle lens of claim 1, wherein the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens are made of a plastic material. The wide-angle lens of claim 1, further comprising an aperture disposed between the third lens and the fourth lens.